class Solution {
public:

    int fib(int n) {
        if (n <= 1)
            return n;
        vector<int>dp(n + 1);
        dp[0] = 0; dp[1] = 1;

        for (int i = 2; i <= n; i++)
        {
            dp[i] = dp[i - 1] + dp[i - 2];

        }
        return dp[n];


    }
};
class Solution {
public:
    int climbStairs(int n) {
        if (n <= 2)
            return n;
        vector<int>dp(n + 1);
        dp[1] = 1;
        dp[2] = 2;
        for (int i = 3; i <= n; i++)
        {
            dp[i] = dp[i - 1] + dp[i - 2];
        }
        return dp[n];









    }
};
class Solution {
public:
    int minCostClimbingStairs(vector<int>& cost) {
        vector<int>dp(cost.size() + 2);
        dp[0] = 0;
        dp[1] = 0;
        for (int i = 2; i <= cost.size(); i++)
        {
            dp[i] = dp[i - 1] + cost[i - 1] > dp[i - 2] + cost[i - 2] ? dp[i - 2] + cost[i - 2] : dp[i - 1] + cost[i - 1];





        }
        return dp[cost.size()];













    }
};
class Solution {
public:
    int uniquePaths(int m, int n) {

        vector<vector<int>>dp(m, vector<int>(n));
        for (int i = 0; i < m; i++)
            dp[i][0] = 1;
        for (int i = 0; i < n; i++)
            dp[0][i] = 1;
        for (int i = 1; i < m; i++)
        {
            for (int j = 1; j < n; j++)
            {
                dp[i][j] = dp[i - 1][j] + dp[i][j - 1];

            }



        }
        return dp[m - 1][n - 1];




    }
};
class Solution {
public:
    int uniquePathsWithObstacles(vector<vector<int>>& obstacleGrid) {
        int m = obstacleGrid.size();
        int n = obstacleGrid[0].size();
        vector<vector<int>>dp(m, vector<int>(n, 0));

        for (int i = 0; i < m && obstacleGrid[i][0] == 0; i++)
        {
            dp[i][0] = 1;



        }
        for (int i = 0; i < n && obstacleGrid[0][i] == 0; i++)
        {
            dp[0][i] = 1;
        }

        for (int i = 1; i < m; i++)
        {
            for (int j = 1; j < n; j++)
            {
                if (obstacleGrid[i][j] == 1)continue;
                dp[i][j] = dp[i - 1][j] + dp[i][j - 1];




            }
        }
        return dp[m - 1][n - 1];
    }
};